This may not be a food chain issue – it could be people from a place with a large ST398 reservoir of cases or there could be a hopsital staff member who is the sentinal case
In 2007 the Scottish MRSA Reference Laboratory carried out PFGE, using smaI on about 6,000 MRSA isolates referred by Diagnostic Laboratories and three were repeatedly found to be non-typeable. All three isolates were had identical PFGE patterns when the restriction enzyme apaI was used and all had the spa type t034. They were resistant to no antibiotic groups tested other then beta-lactams and, specifically, were sensitive to tetracyclines. They were SCCmec type III. Two of the isolates were typed by MLST and both were ST368. These features show them to be different from most reported ST398 isolates but isolates with similar antibiograms, spa types and SCCmec types have been reported from both Europe and Canada. All three patients had infections which responded to appropriate treatment. Epidemiological investigations of the patients, carried out by local hospital Infection Control Teams, were directed towards finding associations with pigs or pig farming but no such associations were found. The only link discovered was that all three had been in-patients in the same hospital, though not in the same ward or in the same department.
